Switch box for railway, tramway points, or similar

ABSTRACT

Switch box for railway, tramway, or similar comprising a drive unit (M,  3, 4, 5, 5′, 5″, 5′″, 6 ) for the shifting motion of the blades (A 1 , A 1′ , A 2 , A 2′ ) and at least one group of linear transmission ( 12, 20, 21, 24 ) of the drive motion to the blades, movable device ( 24, 124 ) to lock the blades in their respective closed positions. The groups are housed in a box ( 1 ) which has substantially the dimensions and the shape of a sleeper and which is fitted in the track in place of and with the function of a sleeper. The switch box has movable device ( 23, 24, 124 ) to lock the blades (A 1 , A 1′ , A 2 , A 2′ ) in their corresponding closed positions. The device ( 23, 24, 124 ) are associated with their respective blade (A 1 , A 2 ) and arranged inside the box ( 1 ) in the area of the same and are brought automatically into active locking position when the corresponding blade (A 1 , A 2′ ) reached the closed position, while they are automatically disengaged on activation of the switch box to switch the blade into the position of closure of the blade (A 2′ , A 1 ) opposite.

BACKGROUND OF THE INVENTION

The invention relates to a switch box for railway, tramway points, orsimilar, comprising a group operating the motion of translation of theblades of the switch, and at least one group of linear transmission ofthe operating motion of the blades, movable means locking the blades intheir respective positions of closure, said groups being housed in a boxwhich has substantially the dimensions and the shape of a sleeper andwhich is fitted in the track in place of and with the function of asleeper.

At present switch boxes of this type are known.

From WO 94/27853 a switch box of this type is known in which, however,only the operating groups the groups of linear transmission of theoperating motion and the groups locking the blades in the closedpositions are located inside the box. At a central slide, housed in thebox branch out drive rods to operate the blades which are external tothe same. The group locking the blades in the closed position acts onthe very slide and not on the blades, while no means are providedallowing kicking of the blades, that is, the disengagement of the samefrom the locking means, under the action of a preset force whichoperates on the blades in direction of displacement of the same.

A further switch box of the type described at the beginning is knownfrom the U.S. Pat. No. 4,093,163. In this case, also the link rods tothe blades are housed in the box in shape of a sleeper, while neithermeans of lockswitching, nor means of kicking are provided.

SUMMARY OF THE INVENTION

The invention has the purpose to realize a switch box for railway,tramway points, or similar, of the type described at the beginning, insuch a way, whereby means are provided in the same suitable to guaranteeall of the functions of locking, lockswitching and or kicking of theusual switch boxes all the elements being mobile, with the exception ofthe blades integrated inside the box shaped like a sleeper, and the samebeing realized with an extremely simple construction, of reduceddimensions and such to ensure the housing in the defined availablevolume, as well as of safe and sure operation.

In particular, the invention aims at the realization of a switch box inwhich movable means of locking the blades in the corresponding positionof closure are provided both by the linear transmission unit of theoperating motion, as well as directly by the actual blades, all to reachthe maximum operational surety and safety of the switch box.

The invention has also the further purpose to realize a switch box ofthe type described at the beginning that can be used with fewmodifications also with the so-called english type points.

The invention attains the above mentioned aims with a switch box of thetype described at the beginning, in which are provided movable means forlocking the blades in the corresponding closed position which areassociated with the respective blade and arranged within the box in thearea of the same blade and which are brought automatically into theactive locking position when the corresponding blade reaches theposition of closure, while they are automatically disengaged at theclosed position of the opposite blade at the moment the switch box isactivated to operate the blade.

The switch box, has means of linear transmission, formed by a saddle,slide or similar which are moved transversally to the track,particularly orthogonally to the same, in the two directions between thetwo extreme end of stroke positions by a group translating 10 the rotarymotion into a linear motion and to which are linked a transmission rodfor each of the two blades, while each blade is connected to a levercoupling it to the respective transmisssion rod thanks to correspondingmovable means locking the blade in the closed position.

In particular, the coupling levers of the blades corresponding to thetransmission rods form said movable locking means of the blades.

In a preferred form of execution, the said levers are oscillating andhave a lateral tooth at the extremity opposite to the one of thefulcrum, each lever being coupled with the corresponding blade by ajoint which allows the rotation of the oscillating lever around aperpendicular axis, preferably by means of a ball joint or similar,while the lever cooperates with fixed stops of engagement in the area ofthe blades there being provided between each coupling lever and thecorresponding transmission rod means of control of the angular positionof the same lever such, that, during the activation of the switch, thecoupling levers are brought into position of disengagement by thestationary stops of engagement, before the transfer of the blades takesplace and when the position of closure of one of the two blades isreached, the corresponding coupling lever is moved angularly intoposition of engagement of the tooth of the extremitity behind thecorresponding stationary stop with reference to the direction oftransfer of the closed blade to the position moving away from theassociated rail.

Advantageously, the control means are formed by shaped slots or grooveswhich form control tracks with which at least one appendix protrudingfrom the facing side of the coupling levers engages.

The axis of oscillation of the levers is foreseen in the area of thelocking means to the corresponding blade, while the coupling leverextends itself beyond the blade in direction of the associated rail.

According to a further feature, the coupling levers are movedalternatively from the position of engagement with the stationary stopsto the position of disengagement, thanks to a relative motion of thetransmission rods with regards to the same in particular in an initialor terminal section of the stroke of operation.

A particularly advantageous form of construction consists oftransmission rods with an angled groove in which at least one controlpin of the corresponding coupling engages in motion, in combination witha pair of lateral guide walls of the free end section of transmissionrods associated with the coupling levers. The angled slot or groove hasa section parallel to the mean longitudinal axis of the transmissionrods and which is arranged offset laterally beside said meanlongitudinal axis, while said section extends itself towards the freeextremity of the transmission rods with an inclined section whichterminates substantially in the area of the mean longitudinal axis ofthe transmission rods or, in any case in an intermediate area of thetransversal dimension of said rods. The position of the slot and itsconformation, as well as the projection of the tooth of the angledlevers is dimensioned and fitted in such a way, that in the initialsection of the driving stroke, the transmission rods move relativley tothe coupling levers as long as the lever in the engaged position whichis associated with the blade closed in the start position is brought inposition of disengagement from the stop, while the lever in position ofdisengagement associated with the blade which has to be brought into theposition of closure moves from a substantially intermediate positionbetween the two lateral guide walls into the position where it stopswith the head of the tooth against the facing lateral guide wall, whilethe pins protruding from said coupling levers in the area of the toothand engaged in the angled grooves, position themselves in anintermediate position of the inclined section of said grooves or slots,whereby, the inclinded wall turned in direction of motion of the blades,of each slott becomes, thanks to the limitation of the oscillation ofthe transmission lever associated with the blade which has to be broughtto the position of closure by the lateral guides, the stop surface fordriving the corresponding coupling lever together with the rod, while,as soon as the tooth comes out of the lateral guide the lever is free tooscillate further coming to a position of engagement with the front edgeof the lateral guide. As a matter of fact, as soon as, the lateral guidewall or walls can no longer limit the oscillation of the couplinglevers, the tie that allows the transmission rod to drive the couplinglever is automatically undone.

Advantageously, each transmission rod has a second slot substantiallyparallel and coincident with the mean longitudinal axis of thetransmission rods and in which a pin or similar is seated which ismovable along the rectilinear slot or groove and which with regards tothe angular motion of the coupling lever is coaxial to the couplingmeans of the lever of the blade, for instance to a joint at least of theball type.

According to a further feature of the invention, the transmission rodsare carried by a common saddle supported in translatable manner inorthogonal direction to the axis of the track, the said saddle isconnected to a drive slide by means of movable coupling means which passto a position of disengagement of the rod-carrying saddle from the driveslide when the resistance to the translation of the blades and thereforeof the rod-carrying slide exceeds a certain preset torque, or when aforce is applied in the direction of translation directly on the blades.

In particular the rod-carrying saddle is provided with sliding rollersin a guide integral with the drive slide, the said rollers are supportedspring mounted displaceable transversally to their axis, while eachroller engages with an inclined plane provided in the rolling walls ofthe guide for the rod-carrying saddle, two inclined planes beingprovided, transversal to the sliding direction of the rod-carryingsaddle and with inclinations simmetrically opposite each other for eachrolling surface, each of these inclined planes is associated with aroller of the rod-carrying saddle.

Advantageously, the rod-carrying saddle is fitted in a upper guideintegral with the drive slide orthogonally translatable to the axis ofthe track, two projections in shape of an isosceles trapezoid which arefacing and coincident with each other are provided in the two oppositevertical lateral walls of the guide for the rod-carrying saddle., whilethe rod- carrying saddle is formed by two carriage springs fixed to eachother, with the interposition of the transmission rod, in correspondencewith the extrados sides and foreseen at the free section of the rollersrevolving around vertical axis, the length of the carriage springs beingsuch, that in the condition of engagement of the rod-carrying saddle andthe drive slide, the vertical rollers are provided at the outermostextremity of the corresponding inclined plane in the area of connectionto the vertical lateral wall of the guide.

In combination with the above, the invention furthermore foreseesmovable locking means of the the drive slide in the two end of strokepositions of closure of the one or the other blade.

Said means have advantageously rocker type means of control ofdisengagement and which are associated with the coupling means of thedrive slide to a linear drive actuator, an initial relative stroke ofsaid coupling means of the slide to linear actuator is provided beforethe mechanical coupling between the two said parts is made, during thesaid stroke the locking means of the drive slide are brought intocondition of disengagement of the same slide.

The invention also relates to a switch box described at the beginningfor an english type points, in which the means of locking the blades inposition of closure, are only associated with the outermost blades ofthe four blades provided, while each of the two internal blades islocked in position of closure thanks to a rigid mechanical connectionwith the external blade which assumes the closed position of the sametogether with the internal blades.

The invention presents further features and perfectionings which are thesubject of the claims below.

The features of the invention and the advantages derived from the sameare better prooven by the Is following description of an executiveexample illustrated as non-limiting claim in the enclosed drawing inwhere:

BRIEF DESCRIPTION OF THE DRAWINGS

The FIG. 1 shows a plan view of a so-called english type point with aswitch box according to the invention.

The FIG. 2 shows a cross-section according to a vertical planetransversal to the track of a switch box according to the FIG. 1.

The FIG. 3 shows an enlarged detail of the cross-section according tothe vertical plane of FIG. 1, in the area of one blade and one rail.

The FIGS. 4 and 5 show a detail relating to the drive slide and to themovable locking means of the same, in the locked and unlocked positionrespectively before the start of the translation.

The FIGS. 6 and 7 show two transversal cross-sections of the saddle andof the movable locking means according to FIG. 4, according to the lineVI—VI and VII—VII respectively.

The FIG. 8 shows an enlarged plan view on the transmission rod-carryingslide in the closed position of translation with the guide integral withthe drive slide.

The FIG. 9 shows an enlarged lateral cross-section in elevation of therod-carrying saddle and of the drive slide.

The FIG. 10 shows a lateral cross-section of the rod carrying saddle andof the drive slide.

The FIG. 11 shows an enlarged partial view of the switch according toFIG. 1 in which only the area of the two external blades and the lockingmeans relative to the same can be seen.

The FIGS. 12 to 14 show some phases of disengagment of the drive slideand the rod-carrying saddle in kicking condition and/or of impediment ofthe blade upon reaching the correct position of closure.

The FIGS. 15 and 16 show the locking means of the rails to the switchbox.

The FIGS. 17 to 20 show different views and different cross-sections ofthe box for the blade position sensors, of the rod-carrying saddle andof the drive slide and the means for transforming the switch box fromkicker to non-kicker.

DETAILED DESCRIPTION

In the FIGS. 1 and 2 a so-called english switch is shown, of the typeforeseen in correspondence to crossings and with four blades. In theenglish type swich two tracks are provided with the rails B1, B1′ andB2, B2′ which co-operate with the blades A1, A1′ and A2, A2′respectively. In a box 1 with shape and dimensions correspondingsubstantially to those of a sleeper, are housed the means for shiftingthe blades A1, A1′ and A2, A2′. The switch box 1 in the shape of asleeper has laterally widening fins 101 (FIGS. 15 and 16) which engagewith the rail clips 2 of the rails B1, B1′, B2, B2′. These have a head102 to overlap the rail foot of the rails B1, B1′, B2, B2′, while theremaining part consists of a tail which is clamped by means of bolts tothe fins 101. According to an advantageous perfectioning, one or bothsurfaces of contact facing each other of the rail clip 2 and of the fins101, can have teeth, or better a knurling parallel to the longitudinalaxis of the track. This allows to obtain both a better registration ofthe relative position of the two parts, as well as a better clampingwith regards to a relative translation between fin and rail clip 2.

The switch box 21 in the shape of a sleeper extends itself for a certainlength also outside the track substantially in a dimension correspondingto the sleepers and in one of said external extentions of theextremities is housed a drive motor generally of the electrical typeindicated with M. The motor M activates by rotation by means of a bevelgear 5, 5′ transmission a threaded rod 3 which is connected to theoutput shaft 5″ of the transmission by means of a coupling 4 which canbe of any type also of the type that disengage under condition of stressgreater than a preset torque or clutch type.

Advantageously as evidenced in greater detail in FIG. 3, in combinationwith the drive motor M it is possible to provide means for manualactivation which can consist of a crank 6 with a shaft 106 at the end ofwhich a bevel gear 206 is provided that engages with a bevel gear 5′″ italso revolving together with the output shaft 5″ of the transmissionwhich is coaxial the bevel gear 5′ connected to the motor. The two bevelgears 5′ 5′″ are coaxial and have different diameters to ensure theappropriate transmission ratios suitable for driving with the motor Mand for manual drive with the crank 6. The crank 6 can be inserted intoposition of engagement with the bevel gear 5′″ of the transmissionthrough an opening 7 in shape of a revolving support sleeve of the box 1equipped with a lid 107.

A Nut screw 8 is inserted on the threaded rod 3 which is housed in amanner to move freely axially between two opposite end of stroke stops 9which are provided at the extremity on a first drive slide 12. The driveslide 12 can slide in the two directions in the longitudinal sense ofthe threaded rod 3 on the bottom of the box 1 thanks to the wheels 13.The nut screw 8 is connected in a reciprocally non revolving manner andtranslatable together thanks to a radial key 10 to a slide 11 which istherefore movable relative to the drive slide 12 between the two end ofstroke stop walls 9 (FIGS. 7, 8).

The free travel of the nut screw 8 between the two end of stroke stops 9is inferior to the global travel necessary to shift the blades betweenthe two positions of closure of the blades A1, A2 and A1′ and A2′respectively to the corresponding rail. Therefore at the start of eachphase of activation of the switch, the nut screw 8 and the slide 11carry out a certain idle travel. This travel is used to activate insense of disengagement the locking means of a first drive slide 12.

The drive slide 12 is provided with wheels 13 and has in the middle areaof bottom recess 112 provided with two notches 212 engaging a lockingtooth 14.The locking tooth is supported by spring loaded means 15 whichpush it firmly in position of engagement in the notches 212 andprotrudes out of at least one lateral side of the slide 12 at least inthe area of the notches 212, preferably of both sides of the drive slide12. The slide 11 has in a position protruding from the lateral sides ofthe same respectively one roller 111 of a pair of coaxial rollers. Therollers 111 engage with cam tracks 116 realized by appropriate profilingof an longitudinal end edge in the example the lower one of the twolevers 16 oscillating between themselves perfectly aligned, coincidentand symmetric and which are fulcrated on the same shaft 316 which issupported by two stationary elements 616 placed on the two sides of thedrive slide 12 and between which the said slide can freely pass duringits travel. The two oscillating levers 16 extend themselves beyond thefulcrum shaft 316 towards the middle area of the drive slide 12. The twooscillating levers 16 extend themselves along the two sides of the slide12 up to the area of the slide 11 and the nut screw 8. On the sideopposite to the nut screw 8, the oscillating levers terminate with apressure head 416 which engages with the section of the locking tooth 14of the drive slide 12 protruding out of the sides of the same.

The whole is realized in such a manner, whereby in position of end ofstroke of the driving slide 12, the rollers 111 of the slide 11connected to the nut screw 8, come to engage with the recessed area ofthe profiled edge of the lower end of the levers 16, whereby theopposite extremity of pressure of the tooth is lifted from the lockingtooth and this can under spring load penetrate into the notch 212 of thedrive slide 12. Upon movement in the opposite direction of the driveslide 12, the nut screw 8 and with it the slide 11 performs a certainidle travel that is with regards to the same slide 12, and the rollersof the slide 11 come to engage with the protruding area of the profiledlower front edge of the oscillating levers. In this condition, thepressure ends of the oscillating levers 16 engage with the tooth pushingit out of the notch 212 against the action of the spring. In this mannerthe drive slide 12 is released with regards to its translation beforethe nut screw 8 and the slide 11 come to stop against the end of strokewall 9, that is before the slide 12 starts to be driven or pushed. Theleaf spring associated with the tooth, not only retains the tooth inposition of engagement in the notches 212, but also presses under springload the levers 16 against the rollers 111.

The FIGS. 4 and 5 show the starting phase of the travel unlocking thedrive slide 12 by the nut screw 8 and the slide 11. In FIG. 4, the slidehas reached the end of stroke position corresponding to a motion to theleft in direction of the arrow F1. The reversal of the direction ofdisplacement of the slide indicated with F2, causes a first idle travelof the nut screw 8 and of the slide 11 until they come to a stop againstthe wall 9. During this travel the rollers 111 have come into contactwith the protruding area of the profiled lower leading edge 216 of thelevers 16, whereby the extensions 416 acting on the tooth 14 pushed itout of the notch 212 and the slide 12 is free to slide when the nutscrew 8 and the slide 11 have come to a stop against the end of strokewall 9. Therefore further displacement of the nut screw 8 along thethreaded rod 3 causes the drive slide 12 to move in direction of thearrow F2.

The end of stroke positions of the drive slide 12 are defined by astationary stop 60 integral with the bottom of the box and through whichpasses an axial extension 412 of the slide 12 which has an enlargedstriker 512 on the extension at its free extremity. In the two end ofstroke positions one of the two faces of the end of stroke stop 6 comesinto contact with the enlarged striker 512 on the extension 412 and thefront end of the slide 12 respectively on which said extension isfitted.

On the drive slide 12 in a superimposed position is an integral guide 19for a rod carrying saddle 18 which is integral with the translation ofthe drive slide 12, thanks to a vertical pin or other fixed joint 618and slides along the longitudinal side walls of the guide 19 in the box1 thanks to the rollers 218. The rod-carrying saddle 18 is of tubularconstruction, and the side walls of the same have a plan form in shapeof isosceles trapezoids, forming at the opposite ends of each side wall318 of the rod-carrying saddle 18 inclined surfaces 518 in a directionsimmetrically opposed to each other and converging towards the centralarea of the very slide 18. In the central area the rod carrying saddle18, has on the bottom and on the top side, a double slide guiderespectively, that is on both sides or one side 418 for instancelongitudinal central grooves, or half of the same, in which theextremities of a central rod 120 are housed. The central rod 120 isconnected to the rod-carrying saddle 18 thanks to a pair of carriagesprings 220. Each of the two carriage springs is connected with theextrados side and in a simmetrical position with regards to the othercarriage spring to the central rod 120, whereby the plan seen from abovehas substantially the shape of an “X”, cut vertically in half by the rod120. Each of the free extremities of the carriage springs 220 has aroller 320. The carriage springs 220 are dimensioned in such a manner,that each roller 320 engages with an inclined surface 518 of therod-carrying saddle 18. In particular, the rollers 320 at theextremities of each carriage spring 220 engage for each carriage springrespectively with the inclined surfaces 518 on the end sides of the veryside of the rod-carrying saddle 18 towards which the carriage spring isfaced.

The central rod 120 is fixed to the carraige springs 220, substantiallyat one single point, in particular in correspondence of the point ormore precisely of the tangential band of the carriage springs 220 tosaid rod 120 by means of a locking clamp 420.

The central rod 120 connects at both its extremities thanks to thejoints 22 with the transmission rods 21 which extend themselves up tothe area underneath the corresponding rail B1, B1′ , B2, B2′. Theextremity 121 of the transmission rods is in shape of a plate, in thehorizontal example and slides between two lateral guide walls 23. In theextremities 121 of the transmission rods 21 a first elongated slot 221is made in the top face which has a certain preset length and isforeseen closer to the coupling 22 to the central rod 120 of therod-carrying saddle 18 and at a preset distance from this first groove221, in the end area a second angular elongated slot 321. The first slot221 is rectilinear and the axis of the same is parallel and coincidentwith the central longitudinal axis of the corresponding transmission rod21. The second slot 321 forms an obtuse angle and has a branch parallelto the central, longitudinal axis of the corresponding transmission rod21, but laterally offset relative to the latter, substantially in ameasure corresponding to the length of the tooth 124 of an oscillatinglever 24, and a transversal, inclined branch which substantiallyterminates in correspondence to the central area of the transmission rod21. The length of projection of the second slot 321 on the longitudinalaxis of the corresponding transmission rod 21 is substantially identicalto the total length of the first slot 221.

On the extremity 121 of each transmission rod 21 rests an oscillatinglever 24 which is angled at its extremity in correspondence to the freeextremity of the transmission rod 21 in order to form a coupling tooth124. From the lower rest surface of the oscillating lever 24 depart in aposition coinciding with the slots 221 and 321 two transversal pins 224and 324 which engage in the corresponding slots 221 and 321 of theextremities 121 of the transmission rods 21. A pin 224 is provided incorrespondence of the extremity of the oscillating levers 24 facing therod-carrying slide 18, while the other pin 324 is provided in an alignedposition with the first 224, with reference to the longitudinal axis ofthe longer branch of the oscillating levers 24 and in the area of theangle of the same. The distance between the two pins 224 and 324 issubstantially corresponding to the distance of the projections on thelongitudinal axis of transmission rods 21 of the extremities, on thesame side, of the slots 221 and 321, in such a way, that when the pin224 stops against one of the extremities of the slot 221, the pin 324stops against the end on the same side of the angled slot 321 which inthis case has the function of a guide track of the pin 324 anddetermines an angular displacement in the horizontal plane of theoscillating lever 24, whose travel is sufficient to bring the leveralternately into position of engagement of the tooth 124 on the frontend of the facing wall of the lateral guide 23 and in the position ofdisengagement of the same thanks to a relative displacement betweentransfer rod and oscillating lever 24.

In coaxial position to the locking pin 224 in the rectilinear slot 221of the transmission rod 21, from the top side of each oscillating leverdeparts a transversal extension connected to the point which is formedby a bolt 424 with a head 524 in form of a spherical joint seat for aball joint type appendix 25 integral with the blade A1, A1′, A2, A2′, insuch a way, that the oscillating lever 24 is coupled with thecorresponding blade A1, A1′, A2, A2, in a revolving manner at leastaround the common axis with the pin 224 of the very lever 24. Thespherical appendix 25 departs from a small arm 125 fixed on the bladeA1, A1′, A2, A2′, in particular to the longitudinal lateral surface ofthe same.

With refernce to the FIGS. 1 to 14 the construction as per above, allowsto obtain the following operation:

Operation under normal conditions.

Activating the threaded rod 3 whether by means of the motor M or thehelp of the crank, in order to obtain the displacment of the blades fromone initial position of closure of one of said blades to thecorresponding rail in the closed position of the blade opposite to theassociated rail, at the start of the travel of the nut screw 8 and ofthe slide 11 associated with the same, relative with regards to thedrive slide 12, (FIGS. 4 and 5) the rollers 11 activate the lockinglevers 16 so as to release the drive slide 12 from the locking tooth 14.Upon reaching the end of stroke stop 9 on the side facing in directionof travel of the drive slide 12, this starts its travel and drags withit the rod-carrying slide 18 above it together with the rod 120 andtherefore together with the transmission rods 21. In the initialstart-up position, the pins 224 and 324 of the oscillating levers 24coupling with the blades initially closed stop against the extremity ofthe associated slots 221, 321 on the side of the same in front withregards to the direction of translation of the transmission rods 21.Therefore, in an initial phase of the travel of translation of thetransmission rods 21, the transmission rod 21 associated with the closedblade in the start-up position carries out a relative motion withregards to the very blade and to the coupling oscillating lever 24. Therelative motion is such as to bring the lever 24 associated with theblade in position of closure in the start-up condition, into position ofdisengagement from the edge of the lateral guide wall 3, while on theopposite side, the guide rod has executed a relative motion such, thatthe oscillating lever 24 associated with one or more blades which haveto be brought into position of closure assumes a slightly inclinedposition and substantially of rest against the internal surface of theside wall of the guide 23 associated with it. Upon reaching thisposition, the pins 324 of all oscillating levers 24 connected to thecorresponding blades A1, A1′, have reached substantially an intermediateposition between the extremity of the inclined branch and the extremityof the same in the angle area of the corresponding slots 321. Theoscillating levers 24 are retained in this position by effect of thelateral guides 23 against which they slide in their further travelduring which, the arms 24 and with them the blades are driven togetherwith the transmission rods 21. The blade reaches the position of closureand at the same time the tooth 124 of the coupling oscillating lever 24passes beyond the rear edge of the facing side wall of the guide 23,with reference to the direction of translation of the transmission rods21, whereby the further translation of the transmission rods 21determins the subsequent oscillation, especially of the oscillatinglever 24 associated with the blade that has been brought into positionof closure, into the position of engagement behind the facing front edgeof the lateral guide walls. The oscillating lever of the blade thatpassed into the position of moving away from the associated rail issubsequently brought into a central position with regards to the lateralguides 23.

In this way, the blade in position of closure is locked in position.

Upon reaching the position of closure opposite to the one at the start,the rollers 111 of the slide 1 associated with the nut screw 8 reach anew recessed part of the control cam 216 obtained thanks to theprofiling of the oscillating levers 16 which are supported stationary ona lateral support 616 through which passes the drive slide 12, so thatthe locking tooth 14 of the drive slide 12 penetrates into thecorresponding notch 212 of the same, locking it in the position ofclosure it just reached.

With reference to the english type switch shown in the Figures, in whichtwo pairs of blades A1, A1′ and A2, A2′ are provided, as the blades ofthe two pairs must assume the positions of closure constrained to eachother for each pair, one single drive slide 12 is sufficient, with onesingle rod-carrying saddle 20 for all four of the blades. Besides thefact that four blades are provided, the english style switch differsfrom the normal one in that for the blades A2 and A1′ in the centralarea of the switch it is not possible to provide specific means forlocking in position. Therefore, in these conditions, having the blade A1of a pair to assume the position of closure together with the blade A2of the other pair, the same are rigidly constrained together by a rod26, while the locking means, that is the coupling oscillating lever 24,is provided only outside the track and in correspondence of the bladeA1. The same identical construction is also foreseen for the blades A1′and A2′ which assume together the position of closure to the respectiverail.

From the above description it becomes evident that the construction ofthe switch box for a traditional switch with only two blades isperfectly identical to the english type switch and inferable from thesame by simply eliminating the rods 26 and the internal blades A2, A1′.

With particular reference to the FIGS. 12 and 14, the particularconstruction of the rod-carrying saddle 18 makes the switch a kickertype. This means, that the switch can be activated by a train suddenlyarriving from an opposite direction to the arrow T in FIG. 1 and fromthe incorrect track, will act with the wheel on the unlocked blade.

In these conditions, the wheel of the train exerts a force ofdisplacement in direction of closure of the blade not locked to itsassociated rail and if the blade of the switch should not yield thiswould entail braking the same or in any case a derailment.

Thanks to the coupling carriage springs 220 and the rod-carrying saddle18, when on the unlocked blade a force of displacement of the same isexercised in direction of closure to the corresponding rail, and whenthis force is greater than the spring loaded one of the carriage springs220, the rollers of the rear branches of the two opposed carriagesprings 220 slide against the inclined planes 518, overcoming them andcompressing the two associated branches of the carriage springs 220 oneagainst the other, so that the central rod 120 and the associatedtransmission rods 21 are free from the drive slide 12 and can translatein the direction of the force exercised by the blade. The mechanism ofthe coupling oscillating lever which is perfectly independent from theone of the drive slide works in an analogous manner to the one decribedpreviously.

According to an advantageous feature, the inclined planes have a lengthsuch, that the sliding of the rollers from one extremity to the other ofthe same corresponds substantially to the length of the section of theangled slots 321 of the transmission rods that is rectilinear andparallel to the longitudinal axis of the transmission rods so that asevidenced in FIG. 13, as long as the rollers remain on the inclinedplanes 518 and do not reach the intermediate zone of the lateral wallsof the rod-carrying saddle 18, the oscillating levers 24 with the lockedblades do not pass into a position of disengagement. This allows themechanism of transmission to absorb slight mechanical stresses exercisedon the blades, without causing the abandonment of the switch position.

The rod-carrying saddle 18 integral with the drive slide 12 allows toavoid stresses on the drive motor in case mechanical obstacles comebetween the blade and the corresponding rail during the closing phase.As a matter of fact if for example a stone or other prevents the rail toassume the final locking position, the drive slide can in any case bebrought into the position of end of stroke, with a disengagement of thecentral rod 120 of the rod-carrying saddle 18 analogous to the onedescribed in the phase of kicking.

With reference to the FIGS. 1, 3 and 17 and 19, the switch box hassensors for the position of the blades, of the central rod 120 and thedrive slide 12.

For the external blades of the english type switch illustrated, as wellas for the blades of a normal switch the position sensors consist oflimit switches 30 housed in small boxes 31 which adhere to outside theof the rail. The switches 30 are activated by a small rod 32 that passestransversly through the rails, protruding on the inside of the sameagainst which acts the side of the blade facing it.

In the english type switch and the normal switch the end of strokesensors of the central rod 120 and of the drive slide 12 are housed in asmall box 35 on top of the switch box in the central section of thetrack or tracks B1. B1′, B2, B2′.

The FIGS. 17 and 19 show hybrid forms of execution of a small box 35 inthat in combination with each other all the functionalities are providedwhether for the english type switch or for the normal switch. Inreality, as evidenced in FIG. 1, as the english type switch can beequipped with two small boxes 35, the means illustrated with referenceto the FIGS. 17 and 19 can be distributed on said two small boxes.

Through a slot 36 in the bottom of the small box 35, at the inside ofthe same protrudes a slider 37 that is carried by the rod-carryingsaddle, tubular 18 and integral with the drive slide 12. The slot 36 hasa length corresponding substantially to the travel of the drive slideand is oriented in direction of translation of the same. The slider 37co-operates with two limit switches 38 and 38′ which are located at theend sections of the slot 36 at a distance and in a positioncorresponding to the stroke of the drive slide 12 and to the end ofstroke positions of the same. The slider 37 acts thanks to inclinedlead-in surfaces 137 on the trip buttons 138 of the switches.

The position sensors of the central rod 120 are made in a similarmanner. A slot 36 oriented in direction of translation of thetransmission rods 21 and of a length corresponding to the stroke of thesame is provided in the bottom of the small box 35 coincident with thecentral rods 120. Through the slot 36 protrudes in the interior of thesmall box a small segment of the rack 39 which engages with toothedrollers 140 associated with each of the two limit switches 40 arrangedat appropriate distances and in appropraite positions analogous to whatdescribed for the drive slide 12 in the section of the extremities ofthe slot 36. The toothed rollers have an axial tooth 240 on the sidefacing the switches 40 this tooth extending itself over a certainangular amplitude and connects with inclined sides 340 with theremaining section of the front edge of the roller 140. The axial tooth240 trips the pushbutton of the switch 40 and according to the positionof the roller determined by the rack, the pushbutton 440 will bedepressed or not. The passage of the rack over the toothed rollersdetermines therefore the signal of position of the central rod 120.

The central small box relating to a normal switch has the same identicalsensors for the drive slide 12 and for the central rod 120.

Furthermore, in the central small box 35 of the english type switchposition sensors are provided for the internal blades A2, A1′. In thiscase, with particular reference to the FIGS. 9, 17 and 19, a smallactivating rod 41 is foreseen analogous to the one for the outside railA1, A2′ and which passes from side to side through the associated railB1′. B2. The protruding extremity at the side of the opposite rail actsthanks to a pressure plate 141 on a further small rod 42 which issupported sliding in the wall of the small box 35 and which protrudes onthe inside of the same, where it acts against an intermediate point of atransversal oscillating lever 43, the free extremity of which acts in amanner of compression on the pushbutton tripping the limit switch 50.

The small box 35 foreseen in the english type switch can only house theposition sensor of the second internal blade A1′, which is realizedanalogous to what described in the preceding paragraph, or rather italso can house position sensors for the drive slide 12 and the centralslide 120 realized analogous to the one previously described, where inthis case the slider 37 and the rack 38 are associated with other parts1integral with the drive slide 12 and the central rod 120.

With reference to the FIGS. 8, 17, 20 according to a further feature, itis possible to provide means with which to constrain firmly and in amovable manner the rod-carrying saddle 18 and therefore the drive slide12 to the central rod 120, thus enabling and disenabling the function ofkicking of the switch. In particular this can be obtained thanks to atransversal, vertical pin 50 which engages in coincident holes orseatings in the central rod 120. The pin 50 can be inserted manuallythus impeding the heeling of the switch if not thanks to a manualintervention of modification or can be controlled in the two positionsin an automatic manner, for example thanks to an electromagnet 51 whoseactivation or deactivation bring the pin 50 in position of engagement ordisengagement of the central rod 120. The whole can also be made in adifferent manner and with other actuating means.

Also this feature can be provided indiscriminately and withoutnoteworthy variations or modifications whether in the english typeswitch illustrated as an example or in the normal switch with twoblades.

According to an advantageous feature, the pin 50 engages with slots 52in the central rod 120, whose length is such to allow within presetlimits a certain relative motion between the central rod 120 and therod-carrying saddle 18. This in particular to allow the rod-carryingsaddle 18 and the drive slide 12 to always reach the end of strokeposition where the motor M is deactivated also in the case whenobstacles are found between the blade and the closure rail of the samewhich prevent the blade from locking in the end of stroke positionagainst the rail.

The slots 52 have such a length, that the relative travel between thecentral rod and the saddle which in the case indicated above takes placeagainst the action of the carriage springs 220 keep the rollers of thecarriage springs always within the range of the inclined planes 518 ofthe rod-carrying saddle 18. Therefore, the central rod can carry outsmall relative motions with regards to the rod-carrying saddle 18 and tothe drive slide 12, but can never be disengaged as in the case of theFIG. 14 when the switch is of the kicker type.

The pin 50 can simply be engaged or alternatively engaged anddisengagned on comand thanks to the electromagnet 51.

To allow for the activation of the switch, also in the case the pin isnot automatically controllable in the active and inactive position,meccanical means are provided which bring the pin 50 automatically inthe inactive position upon activation of the switch. In the presentexample for this purpose lifting means are provided associated with therod-carrying saddle 18 and said means consist of inclined planes 154 ofa cam track 54 that co-operate with a roller 53 supported in a revolvingmanner around an axis transversal to the direction of sliding of thecentral rod 120 and laterally offset in an aligned position with saidinclined planes 154 at the free extremity of the pin 50.

Activating the rod-carrying saddle 18, before the pin 50 reaches thecorresponding extremity of the associated slot 52 in the central rod120, the roller 53 on the pin 50 engages the inclinded plane of the cam54 carried by the rod-carrying saddle 18 and therefore raises inposition of disengagement from the corresponding slot 51 of the centralrod 120, leaving the latter free to move together with the rod-carryingsaddle 18. Upon reaching the end of stroke position of switching, anopposed inclined plane or an interruption of the cam track returns thepin 50 into the angaged position of the other slot 51 in the central rod120 re-establishing the kicker condition.

I claim:
 1. Switch box comprising a drive unit (M, 3, 4, 5, 5′, 5″, 5′″,6) of the transfer motion of blades (A1, A1′, A2, A2′) of a switch, andat least one group (12, 18, 120, 21, 24) for linear transmission of thedrive motion to the blades, movable means (24, 124) to lock the bladesin their respective position of closure, said groups being housed in thebox (1) which has substantially the dimensions and the shape of asleeper and that is fitted in a track in place of and with the functionof the sleeper, characterized by the fact that the movable means (23,24, 124) are provided for locking the blades (A1, A1′, A2, A2′) in theirrespective position of closure, the movable means (23, 24, 124) areassociated with their respective blade (A1, A2′) and arranged inside thebox (1) in the area of the blade (A1, A2′) itself and are broughtautomatically into active locking position upon the corresponding blade(A1, A2′) reaching the position of closure, while the movable means areautomatically disengaged the moment the switch box is activated totransfer the blade into the position of closure with the opposite blade(A2′, A1).
 2. Switch box according to claim 1, characterized by the factthat a linear means (12) of transmission in the two directions betweentwo extreme ends of stroke positions of a group (M, 3, 4, 5, 5′, 5″,5′″, 6) for transforming the rotary motion into linear motion and towhich are coupled a transmission rod (21) for each or more blades (A1,A1′, A2, A2′), while at least said opposite blades (A1, A2′) areconnected to a lever (24) coupling with the respective transmission rod(21) thanks to the corresponding movable means (21, 121, 321, 23, 124,224, 324) locking the blade (A1, A2′) in the position of closure. 3.Switch box according to claim 2, characterized by the fact that thetransmission rods (21) of the drive motion of the blades (A1, A1′, A2,A2′) are carried by at least one drive slide (12), and movablelockingqmeans (8, 9, 11, 15, 16, 216, 212) being provided at the twoextreme end of stroke positions of the drive slide (12) in addition tothe end of stroke stops (60, 412, 512).
 4. Switch box according to claim3, characterized by the fact that the transmission rods (21) can befreed from the mechanical constraint of connection with the drive slide(12) by the action of an external force of displacement on the blades(A1, A1′ A2, A2′).
 5. Switch box, according to claim 3, characterized bythe fact that dedicated end of stroke sensors (3, 31, 32, 35, 36, 37,38, 39, 40) are provided for each of the blades (A1, A1′, A2, A2′), forthe transmission rods (20, 21) and for the drive slide (12).
 6. Switchbox according to claim 2, characterized by the fact that levers (24) areforeseen at least for coupling the outermost blades (A1, A2′) to thecorresponding transmission rod (21), said levers constituting saidmovable locking means of the blades (A1, A2′).
 7. Switch box accordingto claim 6, characterized by the fact that said couplings levers (24)are oscillating and have a lateral tooth (124) at the extremity oppositeto their fulcrum, each lever (24) being connected to the correspondingblade (A1, A2′) by means of a joint (424, 525, 25) which allows therotation of the levers (24) around a perpendicular axis while eachcoupling lever (24) engages with stationary stops (23) in the area ofthe blades (A1, A2′) means (224, 324, 221, 321) provided between eachcoupling lever and the transmission rod (21) to control the angularposition of the same lever (24) such, that, during the activation of theswitch, the coupling levers (24), or at least the coupling lever (24)engaged with one of the blades (A1) in position of closure in thecondition of start-up, are brought in position of disengagement by thestationary stops of engagement (23), before the translation of theblades (A1, A1′, A2, A2′) takes place and upon one of the blades (2′)reaching the position of closure, the corresponding coupling lever (24)is angularly displaced into position of the end tooth (124) behind thecorresponding stationary stop (23) with regards to the direction ofmotion of the blade (A1) closed in position of moving away from itsassociated rail (B).
 8. Switch box according to claim 7, characterizedby the fact that the means of control of the angular motion of thecoupling levers are constituted by slots or shaped grooves (321) whichform control tracks made in the transmission rods (21, 121) and withwitch engages at least one appendix (324) protruding from the facingside of the coupling levers (24).
 9. Switch box according to claim 7,characterized by the fact that the axis of oscillation of the couplinglevers (24) occurs in the area of the means connecting the couplinglevers to the corresponding blade (A1, A2′), while the coupling lever(24) extends itself beyond the blade (A1, A2′) in direction of theassociated rail (B1, B2′) inside lateral guides (23) oriented indirection of motion of the transmission rods (21) and while said rod issubstantially vertical and the coupling levers rest on the associatedends of the transmission rods (21).
 10. Switch box according to claim 7,characterized by the fact the coupling levers (24) are movedalternatively from the position of engagement with the stationary stops(23) to the position of disengagement, corresponding to a relativemotion of the transmission rods (21), in an initial or end stretch ofthe stroke driving the same transmission rods (21).
 11. Switch boxaccording to claim 2, characterized by the following combinations offeatures: the transmission rods (21) have an angled groove (321) inwhich engages in a sliding manner at least one driving pin (324) of acorresponding coupling lever (24); each angled slot or groove (324) hasa section parallel to the mean longitudinal axis of the transmissionrods (21) and which is arranged laterally offset along the side of saidmean longitudinal axis and said section extends itself towards the freeextremity of the transmission rods (21) with an inclined section whichsubstantially ends in the area of the mean longitudinal axis of thetransmission rods (21), or in any case in an intermediate area of thetransversal dimension of said transmission rods (21); stopping means(23) with which engage the lateral teeth (124) of the coupling levers(24); the stopping means (23) limiting the oscillation in direction ofengagement with the associated stops (23) of the coupling levers (24),in the part of the stroke in where the coupling levers (24) are draggedby the transmission rods (21); the position and shape of the slot (324),as well as the projection of the tooth (124) of transmission levers (24)and the conformation and position of the means (230) of engagement ofthe lateral teeth (124) of the coupling levers (24) and of the means(23) limiting the oscillation during the stroke, being dimensioned andarranged in such a manner, that in the initial stretch of the drivestroke, the transmission rods (21) move relative to the coupling levers(24) as long as the coupling lever (24) which is in the engagedposition, being connected with the blade (A1) closed in start-upposition, is brought into position of disengagement by the stop (23),while the lever (24) in position of disengagement, being connected withone of the blades that is to be taken into the position of closure(A2′), is limited relative to its angular displacement by said limitingmeans (23) in such a manner, that the appendix (324) projecting fromsaid coupling levers (24) in the area of the tooth (124) and engaged inthe angled slot (321), positions itself at an intermediate point of theinclined section of said grooves or slots (321), whereby, the inclinedwall turned in direction of motion of the blades (A1, A2′), of each slot(321) becomes connected to the blade (A2′) which must be brought intoposition of closure by the lateral guides, the surface of engagement fordriving the same corresponding coupling lever (24) together with the rod(21) and when in the position of closure of the blade (A2′), thecoupling is lever (24) free from the means (23) limiting the angularmotion, it oscillates further being brought in position of engagementwith the corresponding stationary stop (23).
 12. Switch box according toclaim 11, characterized by the fact that the means limiting oscillationof the coupling levers (24) and the engagement stops of the teeth (124)of the coupling levers (24) are constituted by the assembly of lateralguide walls (23) of the transmission rods (21) and the coupling levers(24), said walls (23) are arranged at a preset distance betweenthemselves, and by the end sides opposite to the centerlines of thetrack of one of said lateral guide walls (23), said end sides arearranged in such a position, that when the tooth (124) of the couplinglevers (24) has just passed the same, the blade (A2′) is in position ofclosure, while the lateral guide wall (23) facing in direction of thelateral tooth (124) of the corresponding coupling lever (24) constitutesone sliding and limiting wall in the position in where the appendix(324) of the coupling lever (24) is substantially positioned in thecentral area of the inclined branch of the corresponding drive slot(324) in the transmission rod (21).
 13. Switch box according to claim 1,characterized by the fact that each transmission rod (21) has a secondslot (221) substantially parallel and coincident with the meanlongitudinal axis and in which is housed a pin (224) of thecorresponding coupling lever (24) or similar which is movable along therectilinear slot or groove (221) and which relative to the angulardisplacement of the coupling lever (24) is coaxial to the means (424,524, 25) coupling the lever (24) to the blade (A1, A2′), or a joint atleast of a rotary type.
 14. Switch box according to claim 13,characterized by the fact that the transmission rods (24) are connected(120, 220, 320, 518) to a common rod-carrying saddle (18) supported in amovable manner substantially in a direction orthogonally to the axis ofthe track, the said rod-carrying saddle (18) is connected permanently toa drive slide (12), while the transmission rods (21) are coupled to therod-carrying saddle (18) by movable coupling means (220), 320, 218, 518)which pass into position of disengagement from the same and from thedrive slide (12) when the resistance to the translation of the blades(A1, A1′, A2, A2′) exceeds a certain preset torque, or when a force isapplied in the direction of motion directly on the blades (A1, A1′, A2,A2′), whereby the same rods of transmission (21) are translated relativeto the rod-carrying saddle (18) against a preset torque coupling thesame to the rod-carrying saddle (18).
 15. Switch box according to claim14, characterized by the fact that the transmission rods (21) arecoupled to the rod-carrying saddle (18) by means of a central rod (120)which has rollers (320) revolving in the sliding direction of the sametransmission rods (21) are supported in a spring loaded manner (220)movable transversally to the sliding direction of the transmission rods(21) against a preset spring loaded force, while each roller (320)engages with an inclined plane (518), foreseen in the rolling walls(218) on the rod-carrying saddle (18), two inclined planes (518) beingprovided, relative to the sliding direction of the rod-carrying saddle(18) and with inclinations simmetrically opposite each other on each ofthe two opposite rolling walls (218) for the rollers (320), beingforeseen for each inclined plane (518) at least one corresponding roller(320) connected to the transmission rods (21) to a common centralcoupling rod (210).
 16. Switch box according to claim 14, characterizedby the fact that the central coupling rod to the transmission rods (21)has two rollers (320) for each rolling wall of the rod-carrying saddle(18), said rollers (320) are supported at the extremities respectivelyby a carriage spring (220) and the two carriage springs (220) beingfixed to each other, on the two longitudinal sides of the centralconnecting rod (120) in correspondence with the extrados sides of saidsprings (220) and the length of the carriage springs (220) being such,that in condition of engagement of the central rod (120) with therod-carrying saddle (18) and the drive slide (12), the rollers beingforeseen at the outermost extremity of the corresponding inclined plane(518).
 17. Switch box according to the claim 4, characterized by thefact that the rod-carrying slide (18) is mounted on an upper guide (19)of the drive slide (12) and has two opposed lateral walls oriented inthe sliding direction of the transmission rods (21) on the walls ofwhich are provided two projections (218) in shape of an isoscelestrapezoid which are facing and coincident between themselves and whoseinclined sides form the inclined planes (518) engaging with the rollers(320) of the central rod (120) at the two opposite ends of which areconnected two transmission rods (21).
 18. Switch box according to claim14, characterized by the fact that movable locking means (3, 8, 9, 10,11, 12, 212, 14, 15, 16) are provided for the drive slide (12) in thetwo end of stroke positions of closure of the one or the other blade(A1, A1′, A2, A2′).
 19. Switch box according to claim 18, characterizedby the fact that said movable locking means of the drive slide consistof oscillating means (16) for the disengagement of a locking tooth (14)elastically pressed in a stable manner (15) in direction of engagementin one or more notches (212) distributed along a longitudinal side ofthe drive slide (12).
 20. Switch box according to claim 19,characterized by the fact that a rocker is provided, constituted by atleast one oscillating lever (16) oscillating around an axis (316)transversal to the run of the drive slide (12) and which extends itselfparallel to said run, said axis (316) of oscillation is stationary withregards to the drive slide (12), forming at one extremity of theoscillating lever a means of pressure on the locking tooth (14) of thedrive slide (12) for displacing the same alternatively into a positionof engagement and a position of disengagement with one of the notches(212) in the cooperating walls of the drive slide (12), while the otherpart of the oscillating lever, on the opposite side of the axis of afulcrum (316), shaped in form of a control cam (216) which engages withat least one roller (111) movable together with said means (8, 9)coupling the drive slide (12) to the linear actuator.
 21. Switch boxaccording to claim 20, characterized by the fact that the rocker isconstituted by two levers (16) integral and coincident with each other,each of which extends itself along the lateral longitudinal sides of thedrive slide (12), said oscillating levers (16) being fulcrated on thesame axis (316) revolving in lateral supports (616) and make the rockera bridge type structure through which and under which passes at leastone section of the drive slide (12) of a length substantiallycorresponding to the actuating stroke of the same, while the slider (8,10, 11) associated with the linear actuator (3, 8) has a roller (111)for each lever (16) of the rocker and is movable between two end ofstroke walls (9) which are transversal to the stroke of the drive slide(12), facing and distanced to each other in a measure corresponding tothe stroke of the control rollers (111) for the disengagement of thedrive slide (12) from the locking tooth (14).
 22. Switch box accordingto claim 21, characterized by the fact that control tracks in shape of acam (116) on the levers of the rocker (16) are provided on the lower endside of the same, while the rollers (111) connected to the slider (8,10, 11) are revolving around horizontal and coaxial axis and supportedon the vertical sides parallel to the actuating stroke of the sameslider (8, 10, 11).
 23. Switch box according to claim 22, characterizedby the fact that the oscillating lever (16) is constantly spring loadedagainst the rollers (111) of the slider (8, 10, 11) by the elastic means(15) which press the locking tooth (14) against the drive slide (12),being of such dimensions as to project laterally outwards at least onone side, preferably on two sides from the walls of the drive slide (12)and pressing the rocker (16) onto said projecting section or sections ofthe tooth (14).
 24. Switch box according to claim 19, characterized bythe fact that the means for disengaging the drive slide (12) from thelocking means in the positions of end of stroke of the drive aredirectly controlled by the means (3, 8, 9) coupling the drive slide (12)to a linear drive actuator (3, 8), during a stretch of the strokewherein the means (8, 9) coupling to the linear actuator (3, 8) carryout a relative idle run with regards to the drive slide (12), beforereaching the mechanical engagement of driving or pushing with the saiddrive slide (121, said means of coupling the linear actuators to thedrive slide (12) being provided with control means (11, 111) of theoscillating lever (16), while the means to engage the locking tooth (14)in the corresponding notch (222) of the same drive slide (12) areconstituted by the coupling means (8, 9, 1, 111), which during theterminal stretch of the actuating stroke move together with the samedrive slide (12).
 25. Switch box according to claim 20, characterized bythe fact that the means coupling the drive slide (12) to the linearactuator are constituted by a slider (8, 10, 11) which can slide betweentwo opposed end of stroke stops (103) distanced from each other in ameasure corresponding to the idle run necessary to drive the oscillatinglever (16) into the position of engagement and disengagement of thelocking tooth (14) with one of the notches (212) in the drive slide (12)corresponding to the position of end of stroke of the same, the saidslider (8, 10, 11) is dynamically connected to the linear actuator (3,8) and has at least one roller (111) engaged with the track of the cam(116) profiled on the corresponding branch of the oscillating lever(16).
 26. Switch box according to claim 22, characterized by the factthat the linear actuator is formed by a threaded rod (3) actuatedrevolving by a nut screw (8), the slider being constituted by the verynut screw (8) and a drive slide (11) of the same.
 27. Switch boxaccording to claim 20, characterized by the fact that position sensors(30, 31, 32, 35, 41, 42, 43) are provided for each blade (A1, A1′, A2,A2′), the sensors (35, 40) sensing the two positions of end of stroke ofthe transmission rods (21) and position (37, 38) of the drive slide(12), said sensors being formed by limit switches (30, 36, 40). 28.Switch box according to claim 27, characterized by the fact that theposition sensors for the blades (A1, A1′, A2, A2′) are foreseen on theside of rails (B1, B1′, B2, B2′) opposite to the associated blades (A1,A1′, A2, A2′), and are controlled by a small rod (32, 41) which passesthrough the rails (B1, B1′, B2, B2′) and which acts directly or by meansof mechanisms of transmission (43) on the pushbutton of the switch (30).29. Switch box according to claim 27, characterized by the fact that thelimit switches associated with the transmission rods (21) and the driveslide (12) are formed by sliders (37, 39) which are linked to the samethrough slots (36) in the corresponding walls of the box (1) and whichact on the corresponding switches (38, 40), directly or by means ofmechanisms of transmission (137, 138, 140, 240, 340, 440).
 30. Switchbox according to claim 29, characterized by the fact that the sliders(37) have surfaces to activate the pushbutton (138) of the switches (38)which are in shape of inclined lead-in surfaces (137).
 31. Switch boxaccording to the claim 30, characterized by the fact that the slidersare formed by a segment of a rack (39) which act on rollers with a sideof the head provided with an outer set of teeth (140) and with the otheropposite side of a head provided with an axial profile, or at least withone axial tooth (240), with lateral inclined lead-in surfaces, withwhich said rollers act on the pushbutton of the switches (40) one rollerbeing foreseen for each limit switch (40).
 32. Switch box according toclaim 27, characterized by the fact that the position sensors at leastof the transmission rods (21) and of the drive slide (12) are foreseenin one or more little boxes (35) arranged in the central area of the boxbetween the two rails (B1, B1′, B2, B2′).
 33. Switch box according toclaim 19, characterized by the fact that the movable means (50) forrigidly connecting the transmission rods (21), or the central couplingrod (120) of the same to the drive slide (12), making the switch anon-kicker type.
 34. Switch box according to claim 33, characterized bythe fact that said means are formed by a pin (5) that can be insertedand removed manually.
 35. Switch box according to claim 33,characterized by the fact that said means (50) for rigidly coupling thetransmission rods (21) to the drive slide (12) are formed by at leastone pin which cap be moved by means of actuators (51) alternatively intoa position of active connection and into an inactive position ofelectromagnetical actuators.
 36. Switch box according to claim 33,characterized by the fact that the means suitable to lock thetransmission rods (21), or the central rod (12) on the drive slide (12)are of the type suitable for allowing a relative motion of a limited andpreset amplitude (52) of the transmission rods and the central rodbetween each other.
 37. Switch box according to claim 33, characterizedby the fact that the pin (50) engages, in the two positions of closureof the blades respectively in a slot (52) elongated in direction oftravel of the transmission rods (21) and applied in a central rod (120)connecting the same, the said slots (52) having a preset length. 38.Switch box according to claim 33, characterized by the fact thatelectromangetical (51) or mechanical (53,54) means are associated withthe pin (50) for lifting or lowering the same in active or inactiveposition for locking the transmission rods (21) to the drive slide (12),respectively upon activation of said drive slide (12) and upon reachingthe end of stroke position of the same.
 39. Switch box according toclaim 38, characterized by the fact that said means for lifting andlowering are mechanical means formed by cam tracks (54, 154) carried bythe drive slide and integrally movable with the same and which engagewith control rollers (53) on the free extremity of the pin (50). 40.Switch box according to claim 33, characterized by the fact that inconjunction with a switch of only two blades, each of the two bladesbeing provided with movable locking means (24) in the position ofclosure with the associated rail.
 41. Switch box according to claim 40,characterized by the fact that it is foreseen in conjunction with aswitch with four or more blades (A1, A1′, A2, A2′) of an english typeswitch, in which the blades (A1, A1′, A2, A2′), connect in pairs withrails (B1, B1′, B2, B2′) of a track and are activated together, a singledrive slide (12) and a single rod-carrying saddle (18) being providedfor all the four blades (A1, A1′, A2, A2′), while, only outermost blades(A1, A2′) are provided with movable locking means in the position ofclosure to an associated rail (B1, B2′) and while inner blades (A1, A2′)are locked in the position of closure thanks to a rigid link (55), forexample a connecting rod with the outer blade (A1, A2′) which takes upthe position of closure together with the inner one (A2, A1′). 42.Switch box according to claim 41, characterized by the fact thatposition sensors (30) of the innermost blades (A1′, A2) are housed inthe small central box (35) for the position sensors (38, 40) of thetransmission rods (21) and the drive slide (12), or in a small dedicatedcentral box.